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August Blue Moon by Peter Edwards


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About this observation
Peter Edwards
Time of observation
24/08/2013 - 10:30
The Moon
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This image of the August "Blue Moon" was taken by Peter in West Sussex on 20th August using a C11 at f/10 and a Nikon D40 SLR. It is a mosaic of six separate images. But was it really a blue moon? Well, it depends on how we define it. These days a blue moon is usually defined as the second full moon in a month, but if we go back as far as1943, the July issue of "Sky & Telescope" magazine madereferenceto the term "BlueMoon." Theycited the Maine Farmers' almanac for August 1937, in which the calendar definition of the Blue Moon explained that occasionally one of the four seasons would contain four full moons instead of the usual three. Therefore this late August full moon could be called a Blue Moon. Our current definition arises because seven times in 19 years thereare13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a monthis called Blue Moon. Complicated? :)

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